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[Goatshade]

This is just a re-post of an old request, of whose implementation I never caught wind. If it was implemented, then I apologise and request both a lock and clarification on how it works in MC.

If not, though, I think MC24 would be a good opportunity.

Basically, I'd love to see frame- and key-frame-accurate seeking via [hotkey] + left and right arrow keys, particularly in video. Maybe Ctrl + Arrow and Ctrl + Shift + Arrow, respectively.

It would also be very useful to have a small, hotkey-called dialog window for jumping to a specified time code or frame in a similar fashion to the Ctrl + G-called Go To... function in MPC-HC (see attachment).

Good idea, y/n?

[Goatshade]

No thoughts?

[Yaobing]

Are these what you ask for:

22.0.77 (3/1/2017)
7. NEW: Frame-by-frame forward stepping in video and television playback. SHIFT+Right Arrow.

22.0.80 (3/10/2017)
5. Changed: When video playing (including live TV) is in frame-stepping mode, LEFT arrow causes video to jump back 1 second, regardless what value it is set in video settings.
6. NEW: CTRL+SHIFT+ARROW (left or right) in video playing jumps to the next/previous key frame.  Works only with certain types of video (such as AVi, mp4, mkv).  Does not work with live TV or TV recordings.

[Goatshade]

Oh, nuts. Would you look at that? I missed that somehow. Great news!

What about the dialog box?

[zaza]

Is it scheduled in jr 24 to have Frame-by-frame backwards stepping in video and television playback? 

[Hendrik]

Backwards is not very likely. You can't really go backwards in a video very easily. You can back to the previous seek point and go forward frame by frame.

[Goatshade]

Backwards is not very likely. You can't really go backwards in a video very easily. You can back to the previous seek point and go forward frame by frame.

As someone who is not a programmer, I'd be interested to know what makes this as difficult as it is, and what, presumably, the MPC-HC team did to get it working.

[rudyrednose]

I do not have the proper terms, but here it is, as I understand it:

Compressed video only sends a full frame from time to time. 
Most frames are deltas from the previous frame using movement vectors applied to small pixel blocks. 
Add the lossy aspect of compression and it makes it practically impossible to go backward frame by frame.

You would have to keep in memory all "delta" rendered frames between full frames.  This will not happen in a product such as MC, this would be the realm of professional video editing stations.

Edit: oops, missed that part "what, presumably, the MPC-HC team did to get it working."

[Hendrik]

Rudy is about right why "naive" going backwards doesn't work. Videos cannot be decoded backwards (not to mention that you also cannot read a file backwards, you would have to "guess" where the previous frame was, or search for it)

The only way to do this is to go as far back as is needed (ie. to the previous known seekpoint, or something like that), and then slowly move forward from there until you reach the frame you want, but this is riddled with a lot of complexity to get it accurate, because its entirely different to how moving forwards works. Frame Stepping forward has a native API that you can just tell "one more frame" and stuff just works. I believe this is also how MPC-HC works, but due to the complexity of this backwards-stepping was not implemented when we did forward stepping. You can step back one-second using normal seeks if you're in frame stepping mode and then manually move forwards again, though, but its just not going to be as accurate.

Maybe Yaobing sometime gets bored and adds backwards-stepping (he did the forward stepping), but I wouldn't expect it anytime soon.

[Goatshade]

Fair enough. I'm holding out hope, for what it's worth. MC24 would be a great opportunity, I think.

[SamuriHL]

Sorry to resurrect such an old thread but did we ever get a jump to frame option?  I want to be able to type in the exact frame I want to go to.  Can that be done?